The slow, nonviolent herbivores — some of whom have been at the zoo since the 1930s and are over 100 years old — get a $1-million update to their digs.

Reporting from San Diego — Woe no more for the Galapagos tortoises at the San Diego Zoo.

Although they are the oldest creatures at the zoo, the jumbo-sized reptiles have long been overshadowed by the charismatic vertebrates: pandas, koalas, pachyderms, big cats and even bigger polar bears.

But now the tortoises — some of whom have been at the zoo since the 1930s — have a new $1-million upgrade to their enclosure on the zoo's Reptile Mesa. The refurbished digs are meant to be more comfy for the animals, more eye-catching for zoo visitors.

The zoo has 17 of the Galapagos species, most having arrived as part of one of the first expeditions to the archipelago off Ecuador — the islands that gained fame nearly a century earlier from the work of Charles Darwin.

From the 17 have come 51 hatchlings that have been made available to other zoos. Some of the larger tortoises weigh in excess of 500 pounds and can stretch 6 feet from serrated beak to pointy tail.

To the non-cognoscente, the tortoises may seem an undifferentiated bunch.

But veteran tortoise watchers, such as members of the San Diego Turtle and Tortoise Society, know that each has a distinct personality. Each also has a number on its shell.

Abbot (No. 25) is known for a stubborn streak, sometimes refusing to move even for a carrot or other leafy vegetable. The same is true with Madeline (No. 5), although she will sometimes fall in line when she sees other females being cooperative.

Chips (No. 9) seems the most playful and Emerson (No. 30) the most aggressive. Winston (No. 2B) sometimes blocks the door to the tortoise "bedroom" until he gets fed.

As for connubial activity, Gramma (No. 4), thought to be between 120 and 130 years old, is the most accommodating of the females. Augustus (No. 7) is considered the most lusty of the males, but given the right mood and setting, all the males will seek out a female or two.

"The males are much more opportunistic than the females," said Don Boyer, the zoo's curator of herpetology.

As part of the upgrade, the enclosure now has more water holes and mud wallows, new vegetation and better signage explaining the history (and endangered status) of the species. There is also a small pen where visitors will be able to pet the tortoises, under the watchful eye of a volunteer docent.

Until the zoo's animal-care philosophy changed in the early 1970s, youthful zoo patrons were allowed to ride the tortoises. Many a San Diego family has pictures of junior sitting on the back of a Galapagos tortoise.

The upgrade also includes an expanded area behind the enclosure with improved lighting and ventilation. In colder weather — or what passes for cold weather in balmy San Diego — the tortoises come inside for protection.

The zoo has improved numerous enclosures for its animals in recent years, but the tortoises never rose to the top of the priority list.

Enter Tom Fetter, tortoise enthusiast, longtime patron of the zoo and past president of the San Diego Zoological Society, the nonprofit that runs the zoo.

"Elephants, tigers, lions, other primates — they're all much easier to raise money for," Fetter said. "The tortoises kept being pushed to the back of the queue."

A trip to the Galapagos Islands convinced Fetter and his wife, Jane, that the tortoise venue at the zoo should be improved. In 2009, the Fetters donated $500,000 to the tortoise upgrade project, a "challenge grant" that required the zoo to raise a matching amount.

The response was surprising: more than 1,700 individual donations, 450 of more than $1,000. Planning and construction took about six months before Thursday's coming-out gala for the Fetter Family Galapagos Tortoise Exhibit.

To be sure, the tortoises are a subtle species. They don't roar or gallop; the males and females share the same prosaic coloration; they're nonviolent herbivores, although the males do butt leathery heads in dominance fights.

Mostly they stare into the distance, perhaps thinking about that fellow Darwin who made their island famous.